Pressure exchangers



Feb. 5, 1957 G. JENDRASSIK 2,730,405

PRESSURE EXCHANGERS Filed April 30, 1951 v 5 Sheets-Sheet 2 IIIIIIIII vii/111111, 6

I" W? v I I I Inventor I George Jendhassl' k R arm bYM R;HI- ?I 2. Attorneys United States Application April 30, 193i; sriaiNsnz'sjsif Glaimspriority, application Great BritaiirMay 9", 1950 14 Claims. (Cl. 230-69) Thisinvention relates to rotaryfprssiire 'e'xchangersof 15 thekirid comprising at leasto'ne ring'fof cells for h'eTcoiri pression or" expansion of gas, and pressure exchange means which operate to interconnectp'airs of cells be tween which pressure exchange is'to occur;

When the interconnection of i a pair of cll's' i s estab lished the gas in thecell at higher' pr'e's's'ur'ie expands "and thereby efiects compression "of the gas in the other eel-l; withaconsequent'flow of'gas, hereinafter for convenience icalled' 'transfer gas, through the diic't means;

In the kindof'pressure exchangerrferred' mates-e eachring of cells m'aybe rotary and the prsisiir' exchange duct means may be non-rotary; or the co'rivefs e airan merit may be'adapted, the requirement in such cases beingonly for relative rotation between tlie"diicf-nieailsankl' the cellsi r.

In known pressure exchangersthe sd-calleiieiicliange of pressure between" any two cllsfliri"communication: through the pressure exchange channelsjis not; erly speaking; an" exchange "of pressuredfitli s'ns't t gas in the cell initially at thehigherpress'ure is 'ex'enaea" down to the initial pressureofthe gas 'inffthelow" rssure ce'll while thelatter gas s-imultaneouslyacqui initialp're'ssure of thehigh' pressurejj'cell. In pract pressure 5 exchange'in' known machines 'ridT'm an eqn'aliia'tion' of pressure betweenfthe ells m com a 'munication, so that no compression cellcan"raiih the" highest pressure of the cycle"(i. e." the" p'r'essur fthe fresh 'gas "introdiiced at high pressure scavenging a expansion celi"can reach the lowest pressurei'ofi cycle (i. e. the pressureof the fresfi'ga's intldiicdat ioa itessniescavenging A a I present invenion' l a p I k U theloss'e's inherent inthbpefation ofsulch m'ziclliii J'bY 's'o aifa'ngihg matte'rs that'a corriplete exchangeoip iezs s f betweeri any two co u catingexpansibn and eoiiip es sion 'ells is more'neai ly approached? The present inve"r'1'ticn pr 'ovid ofi-tli kirid 'refer *wh'ii di JTet rriearis Y co'ri'ipri pa'i'ate 'p v kinetieeiie's 'y *stori'n-g portiiin along which tional area is substantially unvarying an'iP-w is 'so dimeiisioiied th t iri opr'atiorithefiiivv' ersisrs -aterthe presi'sxii'iri" the in -er cdiin c1 suesiaiinall' eqnaiisednanthwhereiinilifeonnee n tweeii 'a een ann an on pa'ssa'g' is 'sei rewhfore direction of 'gas fldw in iiie' as'sag r Preferably," in operationfieaolfcelltaliihg f pressure' exchan'ge'fprocess is in cornmnnie ion si'riiiilta nebuslynvitha' pluralityrof said passagesi M One form oi -pressure exchanger according r'to thwim vefition may cornprise a single;'ring of cells for n'ii'ng f a rotor; nd i nen rotary pressure exchange duct-'- means?- whereineach passage of-the duct meaiis comprises tww kinetie ener-gy storing portions traversed inseriesby thew transien gas; eaeh po'rtiom having a rconvergent entry? 70 and/ or a divergent exit, the exit of tlie upstream of the two portions: being-connected tc :the entrysof thvdofih- Patented Feb. 5, 1957 2 stream nice byaconnecting passage of larger crosssection than 'the kinetic-energy V storing portion Another form of pressure exchanger according to the invention may comprise two contra-rotating substantially co-axial 'rotors each comprising a ringofcell's, a'nd'n'onrotaryrpressureexchange duct'means forming structure separating the rotors wherein the duct means over'on'e arc-ot' rotationiof the-rotor consists-of passagesdesig'ned for gasi flow' -in=0ne direction while'th remaining passages, which are arranged overa'n'arc circumterent'ially ofisetrelativetothe first, are' designed'for gas flowin the oppositef lirection;

l in a: further possible; alternative to which the present invention is applicable, the machine may comprise'two contra-rotating substantially- 'co-axial rotors" arranged closely adjacent without intervening stator-structure; each rotor conip rising 1a ring-of cells. In such a piessureexchanger the duct means may be divided into two "parts each part -integral; with the cell structure of one'of' the rotors, the arrangement being such that during the r0ta= tion of the rptors the? two parts registerand operat'as continuous duct means conveying'tran'sfef gas ac'ro'ss' me small axial gap betweenthe rotors;

In'p're s s'ure exchangers according to the invention;'when* a,- cell I at: higher pressure comes intocornmunication'with a e llat"=lower pressure then during'the-firs't part -of *the pi-'s sur exchange process the-speed of"thetransfer-'gasll in thepassage or passages aifectedwill-progressively see t is to; the pressnredifference, until'-,thepres nthelcell sbecome-equala After this,-due-;to the continiiihgflow of gas in the energywtoringpcirtion of the passage or passages the pressure exchange process ainter c ntinues,--but as the pressure difierence'nowacts 3931 e fgas-fiow the velocity of sucl1'flowdecreasesuiitil' 1 reaches its low est value, at whichmomenflthe of pressure between the two cellsunder con? completed, so far as complete exchangezis e w n nriavoidable losses are taken into account;

e Jallj tosible't o compress the gas in the -compres-.-, cell upf'to the initial pressure of the expanding cell, c after beingjexpande'd down to the initiakpressure-of s'se d "ce'll (provided-the volumes of the cells s to be in 'poi t'ant'ltor arrange {matters so ;that; a s" are', as far as fpo's'sible; continually in'contact 11s so that the gas velocity in the channels is 'ned aftertheipres sures-at the ends of beee eequal;

as r cio's'in -(partial oi' complete) of'the passageiends waves sage ofp s s biii'jthiswill'notmaterially alter the pressure exchanging process; especially if gene diffusers are arranged-at the-outflow "end' of the passages. The; waves j of compression and rarification will also contribute to this iirocessof'energystorageand restoration. For proper functioning and in particular the avoidance of reverse flow in the pi's'siireex'change channels it is pfe fe' r alil' e" that ithe 'delsignj of "fthe -pressure exchanger be where: 1

portion of; the passage.

i=-iime auiin which one passage is in cOntact witli a ass.

riflideal case wherethere are no losses it would-be" between" cells "and passages; naturallyonarid' rar'itic'iation may shoot v along the pas;

l=length of the energy-storing part or parts of the passage.

v=volume of a cell.

Ve=sum of the volumes of the energy-storing parts of the passages in communication with one cell.

C=a constant equal to about 2.5

The formula has the physical meaning that the time during which a channel remains in contact with a cell of the time of a full cycle of the resonant system composed by the communicating cells and the channel, or channels, connecting them.

If the time is longer than corresponds to this limit then losses will increase rapidly.

Some constructional examples according to the in vention will now be described in further detail with reference to the accompanying diagrammatic drawings in which:

Figure 1 is a longitudinal section of a pressure cx changer with one cell rotor.

Figure 2 is a cross sectional view of Figure 1 on the line A-A.

Figure 3 is an enlarged view of one of the channels shown in Figure l.

Figure 4 is a fragmentary section along the circumferential plane BB of Figure 3.

Figure 5 is a view similar to Figure 4 but showing a pressure exchanger with two cell rotors.

. Figure 6 is a section along the line C-C of Figure 5.

Figure 7 is a fragmentary section on the circumferential plane D-D of Figure 5.

Figures 8 and 9 are both developments into a circumsector 8 (Figure 2). In order to establish communication between compression cells and expansion of pressure between cells on the compression sector and the other end with cells on the expansion sector. Each pipe or passage comprises straight portions 11, 11 of practically constant cross section, ditfusers 12, 12' and convergent portions 13, 13'. To avoid shock losses the portions 12' and the tangential component of the velocity of the transfer gas. A section 9a of constant but larger cross section connects the part 12 to the part 13.

In Figure 2 the spacing apart of the pipes 9 is somewhat exaggerated.

The machine operates as follows:

As the ro tor 1 rotates the cells leaving the low prescells. the pipes or passages the cells sure zone 4 contain gas at prevailing at 4. Such gas Due to the functioning of arriving at the high presnearly the high pressure will be used according to the application of the pressure exchanger. In general, if used for generation of pressure gas, then heat is introduced (e. g. by combustion) and gas extracted, if as a heat pump then gas is introduced and heat extracted. In the present case (used as a source of pressure gas) it is assumed that the gas removed at 4 is heat-energised by combustion and a portion of such gas is returned to the cells for expansion. The cells arr'ving at the low pressure scavenging zone 6 contain gas expanded nearly down to the pressure prevailing in the zone 6 and such gas is also handled according to application of the pressure exchanger. In the present case it is assumed that such gas is removed and replaced by fresh gas to be compressed.

The functioning of the pipes or passages 9 is as follows:

When a cell destined to undergo expansion comes in contact with a pipe or passage 9 then in general the pressure in that cell is higher than the pressure at the other end of the pipe. Therefore transfer gas flows through the channel owing to the pressure difference, is accelerated, and kinetic energy thus is stored up. The storage takes place mostly in the kinetic energy storing portion 11 or 11' in which the speed will be the highest. The convergent portion 13 ensures a smooth entrance and directs the flow as required. At the end of the energy storing part the diffuser 12 reduces the speed of the leaving gas so that little kinetic energy should leave the channel part 11. The portion 9a remains at a constant intermediate pressure. The gas flow is again accelerated in 13' and 11' and storage of kinetic energy takes place therein. The diffuser 12' reduces the amount of kinetic energy leaving the storage part by reconversion to pres sure energy. The gas speeds in 11 and 11' increase only until the pressures in the cells connected become equal with the pressure in 9a, after which the speed decreases and energy is restored by compressing the cell under compression above the pressure of the expanding cell.

In a modification, an energy-storing portion (corresponding to 11 or 11') may be provided in lieu of the portion 9a. The channels 11 etc. may also be inclined with reference to the end plate (as at 41 in Figure 8).

It is possible to provide the pipes or passages at both ends of the cell rotor.

Lands or sealing portions such as 14 are provided to reduce the leakage around the edges of the cell walls.

,The inlet and outlet ends of the pipes may be connected to the end-plate at diiferent radii.

In Figures 5, 6 and 7, the machine comprises two cell rotors 15 and 16 (each substantially similar to the rotor 1 described above) rotated in opposite directions and supported in bearings at 18, 19, 20, 21 arranged in stationary end plates 22, 23, 24, 25, the two latter being united by intermediate structure 26. The direction of rotation of each rotor is indicated in Figure 7 by the arrows. Between the two rotors are arranged pressure exchange pipes or passages 27, 28 permitting transfer gas to pass from the expanding cells of one rotor into the compression cells of the other.

The functioning of this kind of machine is very similar to the one described above, except that in the two-rotor machine the expanding cells of one rotor work with the compression cells of the other rotor, an arrangement which permits 21 exchange passages and has the great advantage also that the duct area for scavenging at the pressure extremes are not so much obstructed by constructional parts. In

igure' 7 is shown a channel arrangement which takes care of the tangential components of velocity and at the same time is adapted also for energy storage during pressure exchange. The passages have at one end a convergent portion and on the other a diffuser. The functioningof the passages themselves is, in principle, described with reference to Figures 1-4.

The passages 27 may have a greater cross-sectional area much simpler design for the pressure atthe low pressure; region than atthe high pressure. region, as. indicated forexei'mplinbroken; lines infigpre 6..

In Figures 8,, andlfiare the. cell. rotors, ',;31", 29' the. highpressure scavenging. ducts, 38- .guide vanes to direct. the scavenging flow, 39, .39.! are..sealing lands; on the intermediate structure; 26 As. examplesaa. variety. of modified types of passages are shown in Figure 8. 21 are passages as. described above with. reference to Eigure 7, .40 .are. passagesv which are formedto avoid shock due-to the. peripheral speed of the .cell. rotors,.but withoutspecial dii fusers or convergent portions; These passages will preferably have nearly the same radial dimension as the .cellsof the wheelsaiid so.-no.;great change of velocity will take place when gas. entersor leaves .them. Passages 41 have a convergent entrance portionlying in the directionaof. the velocity of. the .gas leaving the cell rotor, a diffuser 43, anda curved outlet. 42 to impart van appro- .priate peripheral velocity. The scavenging is in. parallel, the gas entering. on each side as shown by thearrows, and leaving centrally by the duct 31.

In. Figure 9 the: cells are formed by helicoidalpartit-ions .44. These may have such directionthatN-thegas leaving a t-cell towards the. pressure exchange passages will: have chiefly axial velocity only, the peripheral component being reduced. The passages at 45 have a curved inlet,

whereas passages 46 have a curved: outlet. 7

The guide vanes 38 may also be arranged in the cell rotors, or the ends of the partition walls of the cells may have the curved form required.

It is possible to use more than two substantially-coaxial cell rotors, alternate rotors rotating .in one. .direction, while the others rotate in the opposite direction. Bassages-mayxbe arranged between each adjacentpair of rotors for the pressure exchanging proeesasandducts may be arranged between. therotors for inlet oroutlet to the low and-high pressure scavenging spaces.

-In any construction described above the radial cellwalls may be so shaped that the scavenging gases entering or leaving the cells producea turbine effect which. rotates the rotor or rotors.

What I claim is:

l. A transfergas passage ,arrangement fora pressure exchanger having at least one ring of cells, a system of ducting to supply gas to and from the. cell-ring, passages to interconnect pairs of cells to permit transfer gas flow from one cell of :a pair to the otherand means for effecting relative rotatiombetween the cell-ring on the one hand'and the saiddu'cting system and thesaid passages on the other hand, during which'relatiye rotation there is momentary "communication between cells containing gas at diiferentrpres'su'res, so-{that the pressure in .one cell of an inter-communicating-pair :fallswwhile that in the other rises with consequent flow of gas by way of the said passages, in which arrangement each of the said passages comprises a kinetic-energy-storing portion along which the cross-sectional area is substantially unvarying and a convergent inlet portion to the said kinetic-energy-storing portion, whereby in the designed conditions of operation the gas flow between interconnected cells persists after the pressure in them has substantially equalized.

2. A transfer gas passage arrangement for a pressure exchanger having at least one ring of cells, a system of ducting to supply gas to and from the cell-ring, passages to interconnect pairs of cells to permit transfer gas flow from one cell of a pair to the other and means for effect ing relative rotation between the cell-ring on the one hand and the said ducting system and the said passages on the other hand, during which relative rotation there is momentary communication between cells containing gas at different pressures, so that the pressure in one cell of an inter-communicating pair falls while that in the other rises with consequent flow of gas by way of the said passages, in which arrangement each of the said passages comprises a kinetic-energy-storing portion which is substantially straight: a, progressively divergent outleteportion from the: .kine'ticmnergy-storing portion, v.v'vherehy ,inthe designed conditions of operation the gas. flow between interconnectedycells. persists after the pressure in them has substantially equalized.

3. A transferrgas. passage arrangement for :a pressure exchanger having at leastone ring of cells, a system; of ducting. to supply gas to. and. from, the cell-ring, passages to interconnect pairs of cells to permitytransfengas flow from one cell of a pair toathe other andmeans-for effecting relative rotationbetween .thecell-ringonthe one hand andthe. said. ducting systemandthe said passageson the other hand, during which relative rotation there is momentary communicationbetween' cells. containing gas at different pressurea p-so that. the: pressure in one. cell :of; an inter-communicating pair falls while that in :the. other rises with. consequent flow-of gasjby way of the; said passages, whichaarrangement each offithe said passages comprises .a-ltinetie energy storing; portionv -.along which the-cross-sectionalarea is. substantially unvarying, a convengent inlet; portion toand -a divergent outlet; portion from-said hineticeenergy-storing portion, whereby :in the designed, conditions of operation :the gas: flow between interconnected cells persists after the pressure in them has substanti-ally ;equalized.

4. A t-ran-sfer gas passage arrangement as claimed in claim .3.;-in:which;each of the said passages has an exit end so curved as to discharge the :gas with a substantial component of velocity-in the direction of rotation :of the 1133.0! 2

5. Artransfer gas passagearraugernent..as claimed .in claim 3 in which each of said passages. has an entry end so curved asto ensure substantially shockless entry of gas from the .cellsinto said passages.

=6. A'transfer gas passage arrangement as claimed .in .claim 3 in which each of the said passages has a greater crossesectionalarea at the lower pressure end than at the higher pressure end.

7. A transfe g as passage arrangement for a :pressure exchanger having at least one ring of cells, a system of ducting to supply gas to and from the cell-ring, passages .to interconnect pairs of cells to permit transfer gas flow from one cell of .a pair to the other and. means for effect- ,ingr'elative rotationbetween the cell-ring on the one .hand .and the said ducting system and the said passages on the other hand, .during which relative rotation there is momentary communication between cells containing gas at different pressures, so that the pressure in .one-cell of an inter-communicating pair falls while that in the other rises with consequent flow .of .gas by way ofthe said passages, in which arrangement each .of the said p sages comprises two. kinetic n rg to ing po i ns along each of which the cross-sectional area is substantially unvarying, a central connecting portion separating and interconnecting said kinetic-energy-ston'ng portions in series relative to the gas flow through the said passage and being of larger cross-sectional area than either of said kinetic-energy-storing portions, a convergent inlet portion to each kinetic-energy-storing portion and a divergent outlet portion from each kinetic-energy-storing portion, whereby in the designed conditions of operation the gas flow between interconnected cells persists after the pressure in them has substantially equalized.

8. 'A transfer gas passage arrangement for a pressure exchanger having two contra-rotating co-axial rings of cells, a system of ducting to supply gas to and from the cell-ring, non-rotary passages forming structure separating the two cell-rings and interconnecting pairs of cells to permit transfer gas flow from one cell of a pair to the other and means for rotating the cell-rings, during which rotation there is momentary communication between cells containing gas at different pressures, so that the pressure in one cell of an intercommunicating pair falls while that in the other rises with consequent flow of gas by way of the said passages, in which arrangement each of 'the said passages comprises a kinetic-energy-storing portion along which the cross-sectional area is substantially unvarying and a convergent inlet portion to the said kinetic-energy-storing portion, whereby in the designed conditions of operation the gas flow between interconnected cells persists after the pressure in them has substantially equalized, and in which arrangement some of the said passages are designed for gas flow in one direction therethrough while others are designed for gas flow in the other direction therethrough.

the pressure in one cell of an intercommunicating pair falls while that in the other rises with consequent flow of gas by way of the said passages, in which arrangement each of the said passages comprises a kinetic-energyston'ng portion which is substantially straight and has a progressively divergent outlet portion from the kineticenergy-storing portion, whereby in the designed conditions of operation the gas flow between interconnected cells persists after the pressure in them has substantially equalized, and in which arrangement some of the said passages are designed for gas flow in one direction therethrough while others are designed for gas flow in the other direction therethrough.

10. A transfer gas passage arrangement for a pressure exchanger having two contra-rotating co-axial rings of cells, a system of ducting to supply gas to and from the cell-ring, non-rotary passages forming structure separating the two cell-rings and interconnecting pairs of cells to permit transfer gas flow from one cell of a pair to the other and means for rotating the cell-rings, during which rotation there is momentary communication between cells containing gas at different pressures, so that the pressure in one cell of an intercommunicating pair falls while that in the other rises with consequent flow of gas by way of the said passages, in which arrangement each of the said passages comprises a kinetic-'energy-storing portion along which the cross-sectional area is substantially unvarying, a convergent inlet portion to and a divergent outlet portion from said kinetic-energy-storing portion, whereby in the designed conditions of operation the gas flow between interconnected cells persists after the pressure in them has substantially equalized, and in which arrangement some of the said passages are designed for gas flow in one direction therethrough while others are designed for gas flow in the other direction therethrough.

11. A transfer gas passage arrangement as claimed in claim 10 in which each of the said passages has an exit end so curved as to discharge the gas with a substantial component of velocity in the direction of rotation of the rotor.

12. A transfer gas passage arrangement as claimed in claim 10 in which each of the said passages has an entry end so curved as to ensure substantially shockless entry of gas from the cells into said passages.

13. A transfer gas passage arrangement as claimed in claim 10 in which each of the said passages has a greater cross-sectional area at the lower pressure end than at the higher pressure end.

14. A transfer gas passage arrangement for a pressure exchanger having two contra-rotating co-axial rings of cells, a system of ducting to supply gas to and from the cell-ring, non-rotary passages forming structure separating the two cell-rings and interconnecting pairs of cells to permit transfer gas flow from one cell of a pair to the other and means for rotating the cell-rings, during which rotation there is momentary communication between cells containing gas at different pressures, so that the pressure in one cell of an intercommunicating pair falls while that in the other rises with consequent flow of gas by Way of the said passages, in which arrangement each of the said passages comprises two kinetic-energy-storing portions along each of which the cross-sectional area is substantially unvarying, a central connecting portion separating and interconnecting said kinetic-energy-storing portions in series relative to the gas flow through the said passage and being of larger cross-sectional area than either of said kinetic-energy-storing portions, a convergent inlet portion to each kinetic-energy-storing portion and a divergent outlet portion from each kinetic-energy-storing portion, whereby in the designed conditions of operation the gas flow between interconnected cells persists after the pressure in them has substantially equalized, and in which arrangement some of the said passages are designed for gas flow in one direction therethrough while others are designed for gas flow in the other direction therethrough.

References Cited in the file of this patent UNITED STATES PATENTS 2,045,152 Lebre June 23, 1936 2,399,394 Seippel Apr. 30, 1946 2,461,186 Seippel Feb. 8, 1949 2,526,618 Darrieus Oct. 24, 1950 FOREIGN PATENTS 553,208 Great Britain May 12, 1943 

